MySQL use inner join in PHP - php

Question

I have 2 tables, the unique id's in each table are the same in both tables.
How do I go about joining the data from both tables together in php?
When I normally pull data I do it like this:
$get_board_array = mysql_query("SELECT * FROM posts WHERE user_id_to = '$id' ");
while($posts = mysql_fetch_array($get_board_array))
{
$post_id = $get_post['post_id'];
$html_output .= "<p>".$post_id."</p>";
}
As for pulling the data from separate tables and not getting it all mixed up, I was thinking of doing something like this:
$get_arrayA = mysql_query("SELECT * FROM tableA WHERE age = '36' ");
while($dataA = mysql_fetch_array($get_arrayA))
{
$dataA_id = $dataA['id'];
$dataA_firstName = $dataA['FirstName'];
foreach($dataA_id)
{
$get_arrayB = mysql_query("SELECT * FROM tableB where id='".$dataA_id."'");
while($dataB = mysql_fetch_array($get_arrayB))
{
$dataB_lastName = $dataB['LastName'];
$html_output .= "<p>".$dataA_firstName.$dataB_lastName"</p>";
echo $html_output;
}
}
}
Or would this be just too weird of a thing?
I know how to do it within SQL using inner join but how do I do something like that in PHP and output html?

Answer 1

It is because of you misguide use of wildcard (*) characters. STOP THAT !! This is what happens when arrogant php developers imagine that they do not need to learn SQL. If you need something , then select it.
SELECT
foo.foo_id,
foo.data as paramX ,
bar.type,
bar.something_else
FROM foo
INNER JOIN bar USING (foo_id)
WHERE
foo.state = 'open'
AND bar.type = 3

Answer 2

This (I'm just guessing the schema and your needs) could be a better query for your situation:
SELECT a.id,a.FirstName,b.LastName
FROM tableA a
JOIN tableB b ON b.id = a.id
WHERE a.age = '36'